Lydian stone or black jasper many different siliceous or flinty slate of a grayish or bluish black shade it's employed to test the purity of silver the total amount of alloy being indicated because of the color kept regarding rock whenever rubbed because of the steel
- Lydian stone, or black colored jasper, a number of siliceous or flinty record, of a grayish or bluish black shade. It's utilized to test the purity of gold, the amount of alloy becoming suggested by the color remaining in the rock when rubbed by the steel.
(letter.) Lydian stone, or black jasper, multiple siliceous or flinty slate, of a grayish or bluish black color. Its utilized to check the purity of gold, the quantity of alloy becoming suggested because of the shade kept from the rock whenever rubbed because of the metal.